Measuring transformers of this kind are, for instance, used to find an instantaneous power delivered to a user. In this case, the instantaneous value of an electrical current is measured and after this multiplied with the instantaneous value of a supply voltage. Preferably, the multiplication occurs through use of a Hall element that exists within the transformer used to measure the current.
An arrangement of the above mentioned type is described in the book Hallgeneratoren, Eigenschaften und Anwendungen, F. Kuhrt and H. J. Lippmann, Springer Verlag, 1968, pages 10 through 11 and pages 267 through 275.
The invention has as its object to create a measuring transformer, the installation of which is especially precise, simple and dependable, and which exhibits improved air gap tolerances, without worsening non-linearities or increasing phase errors.